国 上海久通大学 Transmission Direction For worm and crossed helical gear sets it is more difficult and the following figure can help. Right hand Left hand 图上涤夫廷大学 Velocity ratio for fix-axis gear train i4=-马 Z ZaZ6 i6=22Z ZZaZ6Zs 1212 For worm and crossed helical gear sets it is more difficult and the following figure can help. Transmission Direction 1 2 3 4 5 6 1 2 3 4 5 6 7 8 1 2 3 4 i14 = - ——— Z2 Z1 Z4 Z3 i16 = ———— Z2 Z1 Z4 Z3 Z6 Z5 i18 = Z2 Z1 Z4 Z3 Z6 Z5 Z8 Z7 Velocity ratio for fix-axis gear train